If having public transport is such a key factor of the event, why isn't it in the requirements?
Do you know that public and ground transport was not part of the bid requirements?
I'm sure it would be and the EBU assessment team would have looked at this element as well as all the other requirements (eg venue availability and capacity, hotel accommodation for participants, staff and vistors etc etc).
I worked on the assessment of airports and capacities for Euro 2012 in Ukraine and Poland (an interesting exercise in itself!) and we had a comprehensive requirement for air and ground transportation in the bid documents along with many other requirements. There were several teams evaluating the different elements such as ground capacity and facilities, accommodation and training camps etc.
At the end of the day the winning locations were always a compromise as one element would be superb - for example the footy ground, but the city would be short of suitable accommodation or had a sub-standard airport.
So I'm sure Liverpool has a transport strategy for it, but the details are only now coming out as things are confirmed.
It will be interesting to see what happens over the period and what after event feedback will come out.
There are no specific ground transport requirements for Eurovision although ground transport provision is considered when assessing a city's bid and a city deemed to have an inadequate transport network is unlikely to be selected. The three key requirements a city must meet are having an International Airport (or being close to an International Airport if there isn't one within the city itself), an arena with a minimum capacity of 10,000 that could be vacated for a 6-8 week period, capability of providing a press facility to host a minimum of 1,500 journalists, and hotel accomodation for at least 2,000 spectators, delegates and journalists. All bidding cities that met the criteria, with the exception of London and Belfast, were shortlisted. The initial shortlist was Birmingham, Glasgow, Leeds, Liverpool, Manchester and Newcastle, later narrowed down to Liverpool and Glasgow with Liverpool ultimately chosen.
Under EBU rules the government of the host country is allowed input into the selection process but the final decision lies jointly with the EBU and the BBC. It wouldn't surprise me if there was government influence behind the decision to exclude London from the shortlist.
One has to question if Liverpool does meet the criteria given that three previously participating countries (Bulgaria, Montenegro and North Macedonia) chose not to participate this year citing issues with accomodation in Liverpool. But I think that problem would ultimately have been an issue anywhere in the UK, such is the nature of our hotel market. Probably also worth noting that the three withdrawing countries all failed to qualify from the semi finals last year and may not entirely be telling the truth about why they withdrew from this years contest.